Let's simplify each expression one by one.
- For the first expression:
\[ 2a^2 + a^2 - 17 - 3a^2 + a^4 + a^2 + 20 \]
Combine like terms:
Combine the \(a^2\) terms: \[ 2a^2 + a^2 - 3a^2 + a^2 = (2 + 1 - 3 + 1)a^2 = 1a^2 = a^2 \]
Combine the constant terms: \[ -17 + 20 = 3 \]
The entire expression simplifies to: \[ a^4 + a^2 + 3 \]
- For the second expression:
\[ -7a^2 + 2bc - 8c^2 + 4c^2 + 2a^2 - 9 \]
Combine like terms:
Combine the \(c^2\) terms: \[ -8c^2 + 4c^2 = -4c^2 \]
Combine the \(a^2\) terms: \[ -7a^2 + 2a^2 = -5a^2 \]
Combine the constant term: \[ -9 \]
The entire expression simplifies to: \[ -5a^2 + 2bc - 4c^2 - 9 \]
Final Results:
- \( a^4 + a^2 + 3 \)
- \( -5a^2 + 2bc - 4c^2 - 9 \)